Keyboards, monitor displays and other devices for PCs are connected to device interfaces placed in PC bodies itself. In the PC bodies, device drivers compatible with an OS (operating system) are stored in advance. By using these device drivers, a processing device in a PC body can obtain input from an input device and can provide output to an output device.
However, this causes a problem that a lot of resources are required when a plural of device drivers for devices connected to the PC are stored in local resources in advance. Moreover, if a complete set of hardware including the PC itself, input device and output device is not prepared, a user of the PC can not utilize the PC.
An apparatus called a USB (universal serial bus) device server has been developed. The USB device server enables a plurality of PCs to share input devices and output devices (see, for example, non-patent document 1).
The USB device server is connected to a local area network (LAN) and is recognized as a virtual USB port by client PCs connected to the same LAN. Through this virtual USB port, the client PCs connected to the LAN can share a variety of USB devices connected to the USB device server. Thus, there is no need to prepare the same input and output devices for each PC. Non-patent document 1: Silex Technology, INC., “What is USB Device Server?”, online document, date of posting unknown, [searched on a Nov. 14, 2006] on the Internet.